A printing apparatus includes a printing portion configured to perform printing on a printing surface of a medium, a transporting portion configured to transport the medium in a transport direction, a medium supporting portion located upstream of the printing portion in the transport direction, the medium supporting portion including a medium supporting surface configured to support the medium, a preprocessing portion configured to perform preprocessing on the medium supported by the medium supporting portion, and a mount portion facing the medium supporting surface, the mount portion being configured such that the preprocessing portion is detachably mounted thereto. The mount portion includes a position-setting mechanism configured to set a position of the preprocessing portion with respect to the medium supporting surface.